A
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What is it

Acid rain is a result of air pollution. When
any type of fuel is burnt, lots of different chemicals are produced. The smoke that comes from a fire or the fumes that come out of a car exhaust don't just contain the sooty grey particles that you can see - they also contains lots of invisible gases that can be even more harmful to our environment. Acid rain is rain or any other form of precipitation that is unusually acidic. It has harmful effects on plants, aquatic animals, and infastructure.

Power stations, factories and cars all
burn fuels and therefore they all produce polluting gases. Some of these gases (especially nitrogen oxides and sulphur dioxide) react with the tiny droplets of water in clouds to form sulphuric and nitric acids. The rain from these clouds then falls as very weak acid - which is why it is known as "acid rain"
.

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Effects

Acid rain can be carried great distances in the atmosphere, not just between countries but also from continent to continent. The acid can also take the form of snow, mists and dry dusts. The rain sometimes falls many miles from the source of pollution but wherever it falls it can have a serious effect on soil, trees, buildings and water.


Forests all over the world are dying, fish are dying. In Scandinavia there are dead lakes, which are crystal clear and contain no living creatures or plant life. Many of Britain's freshwater fish are threatened, there have been reports of deformed fish being hatched. This leads to fish-eating birds and animals being affected also. Is acid rain responsible for all this? Scientists have been doing a lot of research into how acid rain affects the environment. Acid rain is mostly caused by human emissions of sulfur and nitrogen compounds which react in the atmosphere to produce acids. In recent years, many governments have introduced laws to reduce these emissions.


Definition ( how is it formed?)



"Acid rain" is a popular term referring to the deposition of wet (rain, snow, sleet, fog and cloud water, dew) and dry (acidifying particles and gases) acidic components. A more accurate term is “acid deposition”. Distilled water, which contains no carbon dioxide, has a neutral pH of 7. Liquids with a pH less than 7 are acidic, and those with a pH greater than 7 are basic. “Clean” or unpolluted rain has a slightly acidic pH of about 5.2, because carbon dioxide and water in the air react together to form carbonic acid, a weak acid (pH 5.6 in distilled water), but unpolluted rain also contains other chemicals.[1]
H2O(l) + CO2 (g) → H2CO3 (aq)
Carbonic acid then can ionize in water forming low concentrations of hydronium ions:
2H2O(l) + H2CO3 (aq) CO32- (aq) + 2H3O+(aq)

The extra acidity in rain comes from the reaction of primary air pollutants, primarily sulfur oxides and nitrogen oxides, with water in the air to form strong acids (like sulfuric and nitric acid). The main sources of these pollutants are industrial power-generating plants and vehicles.

Human Activity

The main cause of acid rain is sulfur and nitrogen compounds from human sources, such as electricity generation, factories, and cars. Coal power plants are one of the most polluting. The gases can be carried hundreds of kilometers in the atmosphere before they are converted to acids and deposited. In the past, factories had short funnels to let out smoke, but this caused many problems locally, factories now have taller smoke funnels. However, distribution from these taller stacks causes pollutants to be carried farther, causing widespread environmental damage.

What does it do?

Effects / Acid rain has been shown to have adverse impacts on forests, freshwaters and soils, killing insect and aquatic lifeforms as well as causing damage to buildings and having impacts on human health

Acid rain can also cause damage to certain building materials and historical monuments. This results when the sulfuric acid in the rain chemically reacts with the calcium compounds in the stones (limestone, sandstone, marble and granite) to create gypsum, which then flakes off.

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Result of Acid Rain on trees in a forest.

Where is it having the worst effect?

Water. To people, to animals and buildings even because the acid rain corrodes the limestone etc. on all the buildings.


When was acid Rain first discovered?

Scientists first discovered acid rain in 1852, when the English chemist Robert Agnus invented the term. From then until now, acid rain has been an issue of intense debate among scientists and policy makers
.

What can be done to stop it?

There are many ways that people can stop pollution. One major way is to reduce the amount of trips that you take in your car. Another way that a lot of our pollution is caused is by creating electrical energy. When electricity is created, fuels are usually burned, and this causes the pollution, which causes acid rain. The generation of electric power produces more pollution than any other industry in the United States. Burning coal and other fossil fuels causes most of our pollution. This is why in some places around the world, acid rain is monitored very closely. In 1998, data shows that by using electricity, the pollution that comes with it was responsible for 67% of the sulfur dioxide emissions that caused acid rain that year. Every time that you turn on the lights, that causes the pollution that causes acid rain. Even doing little things that you may think don’t cause pollution sometimes really do. Some things that you can do to make acid rain less of a problem are:


In Your Home


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Only run the dishwasher with a full load

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Only run the washing machine with a full load

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Turn off the lights in empty rooms or when you will be away from home

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Turn off the hot water tank when you will be gone for a long period of time

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Turn down the heat at night and when you will not be home for the night

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Don’t use your air conditioner as much

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Install fluorescent light bulbs instead of incandescent light bulbs

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Try to reduce, reuse, and recycle as often as you can

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Try not to burn a fire as often as you usually do


In the yard


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Keep the pool cover on the pool whenever you are not using it


Transportation


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When you are going to work, you could walk, ride your bike, or take a bus

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Car-pool to a place with someone else

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For alternate fuels, try ethanol, propane, or natural gas

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Take the train or a bus for long trips

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Limit the amount of long trips you take in your car

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Make sure that your vehicle’s air conditioning system isn’t leaking

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Try not to overflow the gas tank

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Make sure that you are traveling at high speeds only when you need to



Where do acids come from?


  • Nitric oxide & sulfur dioxide released primarily from electric power plants & motor vehicles
  • SO2 + water vapor + ozone ---> H2SO4
  • NO + sunlight + O2 ---> NO2 + various atmospheric gases ---> HNO3